<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .pop{
            background: #409eff;
            margin: 20px auto;
            width: 300px;
            height: 100px;
            font-size: 2rem;
            line-height: 100px;
            padding-left: 20px;
            position: relative;
            border-radius: 5px;
            color: #fff;
            filter: drop-shadow(0 0 8px indigo);
        }
        .pop::before{
            content: '';
            background: #409eff;
            position: absolute;
            width: 20px;
            height: 20px;
            transform: rotate(50deg);
            left: -10px;
            top: 50%;
            margin-top: -10px;
        }
    </style>
</head>
<body>
    <div class="pop">测试文本</div>
</body>
</html>